Tauri uses the native webview on the platform, which is presumably why startup values are all over the place. (It's also somewhat suspect to the point of warranting investigation; even using the native webview there seems no reason for something that takes half a second on Windows to take 25 seconds on Linux).

I had this same observation. My guess is because Tauri uses WebGtk and Linux doesn’t really have a “native webview” so it’s kinda shipping the whole thing? The startup time seems like Tauri’s a non-starter for a lot of apps if you want them to be cross platform, had no idea this was a thing.

These startup times do not make any sense. I've developed a little toy app using Tauri+React and it starts pretty much "instantly" in all platforms.

For me Tauri/Wry starts up pretty instantaneous. This is using Wry as the renderer for the DomTerm terminal emulator (https://domterm.org), invoked with 'domterm -Bwry'. This is on Fedora Linux 41 x64. Admittedly using a rather old version of Wry (0.43.1) with webkitgtk 2.46.5 - I haven't had time to update.